Clive Palmer has launched legal action against CITIC over environmental rehabilitation funds for the massive Sino Iron project in WA, just days after his estranged Chinese joint venture partner started separate litigation.

Mr Palmer says his private company Mineralogy, which owns the Pilbara land on which the $18 billion project sits, has started Supreme Court proceedings over $500 million it says CITIC should have put into a remediation fund.

“For 12 years, they’ve been refusing to put any money into it,” Mr Palmer told AAP on Monday.

“So the people of Western Australia have got no protection against the environmental damage that they’ve done at Cape Preston.

“Now we’ve got to go to court to enforce that.”

CITIC began separate legal action on Friday, claiming Mineralogy and Mr Palmer had refused to join the state-owned company in seeking state government approvals for additional land, including for waste rock and tailings storage facility expansions.

“Mineralogy’s ongoing failure and refusal to submit the proposals and take the other steps requested of it has caused, is causing and will continue to cause loss and damage to CITIC subsidiaries,” CITIC chief executive Chen Zeng said.

“The ultimate effect will be a substantial reduction in the scope of operations of the project.

“It may result in the suspension of those operations.”

The WA government has been dragged into the civil action, being a key party to the State Agreement governing the project, and is required to be represented.

Relations between the companies have become so bitter, CITIC refuses to let Mineralogy on site, Mr Palmer says.

In November, Mineralogy won its long-running court battle against CITIC over royalty payments from the project, which the Chinese company built and operates.